Ordinary claims require ordinary evidence, and extraordinary claims require extraordinary evidence. That’s a really straightforward guideline. It’s really useful for evaluating claims of things that supposedly happen or should happen predictably. Things like whether intercessory prayer can heal people, whether homeopathy works, and whether psychics can actually talk to the dead or read minds. It’s doable to set up a carefully controlled study to see if the effect that’s claimed is really there. (James Randi has $1,000,000 waiting for anybody that can reliably demonstrate a paranormal ability under conditions controlled to eliminate confirmation bias and cheating. Nobody’s won it yet!)

But what do we do with events that don’t happen predictably? How do we examine a claim where there isn’t any additional evidence available, because it only happened once? Just because we can’t gather sufficient evidence to show that it’s paranormal doesn’t mean that it isn’t. How do we tackle something like a ghost sighting or a UFO or that one time you were thinking of someone and they called you?

In these cases, we should remember the saying “when you hear hoofbeats, think horses, not zebras”. We should start with the information we have, look at the possible explanations, and figure out which of them is more probable. Only when we have ruled these out might we be justified in concluding that the cause is something unusual and improbable.

When you are trying to explain something weird that once happened to you, here’s the possibilities that I can think of:

It’s a natural occurrence that’s rare or unfamiliar to you

It’s technological

It’s somebody deliberately tricking you

It’s a problem of faulty perception and/or faulty memory, perhaps combined with some of the above

It’s “supernatural”

I’d like to tackle each of these in some detail, so I’ll start with examining the first couple, and come back to the others in later posts.

Natural occurrences:

Rare: There are lots of things that happen naturally, but are uncommon. But they do happen every day, to somebody. Something that has a one-in-a-million chance of happening to someone on any particular day should happen in New York City eight times a day on average. A disease that has a 99% fatality rate still has one person in a hundred survive. That person might think their recovery was a miracle, but it was only what we would expect from statistics. And we only hear from that one survivor, not the 99 who didn’t survive, so our perception is skewed.

And when we think about the probability of something odd happening, we ignore all the odd things that didn’t happen. Perhaps you were thinking of an old friend today, and they called. How many other times have you thought of an old friend and they didn’t call? Thought of a song and then didn’t hear it on the radio? Not found money on the sidewalk right when you needed it? This morning I didn’t narrowly avoid a traffic accident, didn’t unexpectedly see someone I know, didn’t see a familiar face in the clouds, etc. etc. With all the low-probability stuff that could happen, the odds are that every so often some odd coincidence is going to happen to us. But we ignore all the stuff that didn’t happen, and our minds are crap at statistics, so we attach a lot of importance to that event, when it really was just random chance.

Unfamiliar: There are things that happen to people every once in awhile that we misinterpret because we don’t recognize what’s going on. I’m going to use the example of sleep paralysis, which is a reasonably commonplace occurrence that most people are unaware of.

When you are dreaming (REM) sleep, your brain must shut down the connection to your motor functions, and it must also simutaneoulsy turn off both the REM sleep and turn the motor connection back on when you awaken. For most people this happens several times every night without a hitch. If the motor functions don’t turn off, the result could be sleepwalking. Or something even simpler – once I was dreaming about walking, and my brain didn’t keep that motor connection turned off. My legs took a step and didn’t have the expected feeling of hitting the ground because I was lying down, and I woke up very startled, feeling as though I had just fallen. Unnerving, but not really spooky.

But a failure to re-engage the motor control is much more distressing. Commonly known as “sleep paralysis”, or hypnogogic (when falling asleep) or hypnopompic (when waking) hallucinations. Someone may wake up without their motor control switching back on, and be unable to move. This is scary in itself. And often the brain interprets this as there being “something” in the room causing the paralysis. A presence of some kind. And if dreaming has not completely shut off, then the images from the dream are still influencing the perception of the event. In the middle ages this was often interpreted as a visit from a demon or a witch. In modern times, this might be reported as an alien abduction. People will tend to try to associate the strange event with something they can identify, so they impose a story on it that fits their own preconception. (My spouse had an experience like this, that he thought might have made someone think they had been visited by a ghost. After reading about sleep paralysis, he realized that it was a perfect description for what he experienced.)

As a result an episode of sleep paralysis can be deeply frightening and sometimes life-changing. But this is largely a result of being unaware of the commonplace explanation for what appears to be a supernatural event.

Technological:

Take a look at this image:

This showed up in the sky over Norway in 2009. A beautiful glowing perfect spiral! Couldn’t be natural, must be aliens, right? Or angels or fairies or something? It’s definitely a sign!

Except shortly afterwards it was identified as a malfunctioning Russian missile test. A rocket stage was spewing exhaust and spinning out of control, which resulted in this perfect spiral. No aliens, no spirits, just derping technology.

Or, consider the possibility of UFOs. If there actually were alien spaceships visiting us you’d think that they would be seen the most often by the people who spend the most time looking at the sky. Well the group that spends the most time looking at the sky is the amateur astronomers. Do they report more UFOs? No, they report fewer sightings, because as experts on what’s in the sky they are more likely to be able to identify what they are seeing. They are more likely to recognize a weather balloon or a satellite, or all of the other run-of-the mill lights in the sky.(http://blogs.discovermagazine.com/badastronomy/2009/07/21/slamming-the-astronomers-should-see-ufos-myth/)

So before you jump to a conclusion of “supernatural”, be sure you have ruled out the more everyday boring explanations first.

And that “UFO” hovering over the Olympic Stadium in the picture at the top of this post?

Share this:

Like this:

Related

Looking forward to your later posts on this, especially your skewering of the “supernatural”.

I can sort of identify with dreaming of falling. Used to really startle me as I involuntarily moved in reaction. That hasn’t happened for a long time so maybe I have adjusted, but more likely is that I no longer dream of falling.

[…] But they are not evaluated in isolation. The rest of my experience comes into play via my prior. Ubi Dubium at Question With Boldness has a great series about how to handle that one thing you can’t […]